Good time of the day,

I want to ask questions about SIFs for butt weld and Tapered Transition. Both of these SIFs include mismatch. The maximum value of SIF in both cases is 1.9. If mismatch =0 then both SIFs take small values. But even a small mismatch value leads to a large increase in SIF. However, in the theory of pipe SIFs, butt weld is already taken into account, which means the standard mismatch value. The mismatch in any case will be present after the installation of pipes.

1. Practically how do you use these SIFs? Those. when should one decide to use additional SIF on butt weld and Tapered Transition?

2. Should I use Tapered Transition for type B fittings? After all, there the thickness of the fittings is greater than that of a straight pipe. And since the assortment may not match, the difference may be noticeable.

Best regards Pavel